Field
The present specification generally relates to infrared detector devices and, more particularly, to barrier infrared detector devices and structures for reducing dark current, lowering bias voltage, and increasing operating temperature for infrared detectors such as focal plane arrays.
Technical Background
The nBn device structure has been used to improve the operating temperature of photoconductive infrared detectors by blocking the flow of electrons. The nBn device structure generally includes an n-type absorber layer, a barrier layer to block majority carriers, and an n-type contact layer. Such nBn devices have been shown to improve the operating temperature of mid-wave infrared (MWIR) focal plane arrays (FPA) using Ga free InAs/InAsSb super lattice structure (SLS) absorber material. FPA devices using the nBn device structure require some bias to turn on the photocurrent, while the dark current density increases at the same time. To increase the operating temperature further, it is necessary to further lower the bias voltage required to turn on the photocurrent and reduce the dark current.